Quote:
Originally Posted by nelsmar
Just a tip: if you are pulling out that much fuel and you were hitting that load cell and still knocking I personally pull timing out of both the 1.1 & 1.2 cell's in the event you further modified the car or had weather conditions that would result in you hitting those loads cells. Because if you were hitting that false load cell with running overly rich, and you were to hit it again with the correct target AFR you are going to likely knock in those conditions regardless. I try to make sure im not digging a "pit" in my timing table that would cause the car to further advance timing as i hit a larger load cel because I wasn't "smoothly" pulling timing in the region I was getting FLKC. Try hitting that RPM range at a higher gear so that way you can verify exactly where the load cell is that you are knocking to avoid having to do large area ignition adjustments.
Just for comparison I run supercharged cars at these AFR's (11.5-11.8 at redline). Typically getting -1 FLKC simply shifting 0.1-0.25AFR richer resolves this, as well as a -0.3 ignition correction. So if I am seeing 0.25 AFR rich fueling error and i see -1 FLKC at that event i will pull 0.3 from both the current and new "target" load cell. As the next time if I were to hit that load cell it is likely I would be running even leaner and more likely to knock.
Does Australia fuel have ethanol in it? If not I would possibly try restoring the factory MAF scaling and start from there.
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Australian 98 RON is generally Ethanol free
The only pump 100 RON fuel available contains 10% ethanol, basicly 98 RON with 10% ethanol to bump up RON by 2 points, it does lean out your fueling a bit. Logging shows it has better knock resistance especially higher rpm.
My main question now is why the fueling table shows target AFR = 12.5 WOT on gasoline but logs show 11.5 AFR 2% LTFT.
Shiv says in posts this is what he targets ie 11.6-11.8, and that what most peoples logs show. Just wondering why its not getting closer to 12.5 in logs o2 sensor error or MAF ?. In the Thread on OFT wideband sensor" shiv suggests o2 sensor is inaccurate at WOT.
Even if the sensor was inaccurate the ecu would not know so why doesn't it try to get AFR to 12.5 ?